<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        .div {
            width: 200px;
            height: 200px;
            margin: 200px auto;
            animation: test 2s linear 0s infinite alternate forwards;
        }
        @keyframes test {
            /*  高级动画 多关键帧
                以下是第几秒  为总时间的百分比 */
            0% {
                border-radius:0px;
                background-color: #ff409f;
            }
            50% {
                border-radius:100px;
                background-color: #bf00bf;
            }
            100%{
                transform:scale(2,2);
                border-radius:0px;
                background-color: #ff8306;
            }
        }
    </style>
</head>
<body>
<div class="div"></div>
    

</body>
</html>